1. Field of the Invention
This invention relates to a combined fluid injection and inflation system that may be used to assist with both the diagnostic and therapeutic portions of percutaneous transluminal angioplasty (PTA), (balloon inflation/deflation), and with angioplasty procedures in general. The combined injection and inflation system is used to inject fluids such as contrast media (“contrast”) for diagnostic imaging, catheter or guidewire placement, drug delivery or any similar fluid delivery application as well as to provide a balloon inflation capability for balloon angioplasty, balloon assisted stent deployment or other inflation applications. The system may be used with, but is not restricted to X-ray, MR, and ultrasonic imaging modalities, and generally comprises tactile, audible, and/or visual feedback capability so that a health care provider has more direct control of the fluid injection or inflation profile.
2. Description of Related Art
Several hundred thousand percutaneous transluminal coronary angioplasty (PTCA) procedures are performed in the United States each year in cardiac and special procedure imaging laboratories. In most instances, the angioplasty portion of the procedure is preceded by a diagnostic study that determines or confirms the degree and location of stenosis present. Angioplasty is a therapeutic approach that uses small inflatable balloons placed on the tip of a catheter to open blocked vascular tissue. A collapsed balloon is placed near the occluded area of the blood vessel and is inflated to apply pressure to the surface of the blockage and compress it against the blood vessel wall. Often, a power injector is in the procedure room for pre and/or post angioplasty studies to locate and determine the extent of stenosis or it is used for some other related diagnostic study, such as a ventriculogram, to determine heart function. In addition, it is sometimes used after a procedure to assess the effectiveness of any treatment.
Electromechanical devices for inflating balloons associated with catheters are known in the art and are now used as a supplement to or a replacement of manual inflation devices such as that described in U.S. Pat. No. 4,370,982 to Reilly. For example, U.S. Pat. No. 5,460,609 to O'Donnell discloses an automated inflation/deflation system for use in connection with a dilatation balloon catheter. The disclosed inflation/deflation system includes a fluid chamber having a plunger for pressurizing a body of inflation fluid in response to the movement of the plunger. Movement of the plunger is controlled by an electromechanical motor drive unit. The motor drive unit itself is activated in response to a signal directed from a control switch. The system further includes a pressure transducer and a display unit, so that the operator can monitor information relating to inflation pressure and inflation time. In addition, the system includes safety features for effectuating a rapid reduction in balloon pressure.
U.S. Pat. No. 5,273,537 to Haskvitz et al. discloses an inflation system which includes a frame-mounted pressure sensor to measure the pressure through a diaphragm on the exterior of a syringe, a microprocessor controlled display for inflation and duration information, and a control that allows motor-driven operation of inflation/deflation at selected rates or to selected specific inflation pressures. The syringe used in the system is disposable and driven by a plunger rod supported within the frame. The frame further supports a motor for driving the plunger. Other disclosed features of the system include a connected or wireless control means for controlling plunger advancement, piston release, and a display that indicates balloon volume, pressure, and inflation time information. This patent further discloses a control system that allows motor-driven operation of inflation/deflation at selected rates or to selected inflation pressures.
Published Canadian Patent Application No. 2,045,070 by Mizoguchi et al. discloses a syringe used in Digital Subtraction Angiography (DSA) and PTCA (percutaneous transluminal coronary angioplasty) that is driven by a motor. Motor velocity is controlled by a hand or foot control. The allowable ranges of control are preset in the control unit and displayed on a display unit together with control data.
U.S. Pat. No. 5,152,776 to Pinchuk discloses an automated balloon inflation device that uses an indirect pressure measurement as a source for feedback to implement pressure control by the inflation device. The overall system generally includes means for inflation/deflation patterning, a pump for withdrawing and dispensing fluid from a balloon, a pump drive mechanism, and a pressure control mechanism. One drawback with the system disclosed by this patent is the location of the control pressure transducer, which is specifically located between the pump drive mechanism and pump and is not likely to provide accurate pressure sensing information.
U.S. Pat. No. 5,021,046 to Wallace discloses a fluid pressure monitoring system for a balloon catheter that includes a pressure transducer in fluid communication with the interior of the balloon. The pressure transducer includes elements for providing an electrical signal which is a function of the pressure in the interior of the balloon. An electronic digital display is responsive to the electrical signal from the pressure transducer to display the balloon pressure measured by the pressure transducer. The system is adapted for use with a catheter that carries an inflatable balloon to the vicinity of a stenosis, where it is inflated, and the disclosed fluid pressure monitoring system detects and digitally displays to the operator the pressure inside the inflated balloon.
Furthermore, U.S. Pat. No. 5,385,549 to Lamproppoulos et al. discloses an electronically-controlled syringe system for connection to a balloon catheter or other balloon type member, and for automatically monitoring, displaying, and recording inflation data when the syringe system is used for inflation.
Devices for controlling administration of multiple intravenous solutions and medications are also known in the art. For example, U.S. Pat. No. 5,199,604 to Palmer et al. discloses an irrigation system for delivering a selected one of multiple liquid solutions to a treatment site. The irrigation system includes a plurality of solution reservoirs, each including a quantity of a respective liquid solution, a handpiece, a selector valve for fluidly coupling the handpiece to the selected solution and a pump for causing the selected solution to flow to the handpiece for delivery to the treatment site. The irrigation system also includes a heater for heating the liquid solution prior to its delivery to a patient.
U.S. Pat. No. 4,925,444 to Orkin et al. discloses a multiple fluid delivery system adapted to deliver intravenous fluids to a patient from a plurality of fluid sources. The system includes flexible tubing for coupling the respective sources to a fluid junction member. The fluid junction is coupled by an output conduit to a controllable pump which is connected to a patient catheter. The system is adapted to multiplex a plurality of different fluids. The fluids may be mixed in the output conduit as desired. Operator interaction and control of the system occurs either through a display screen or by means of a bar code sensor.
U.S. Pat. No. 4,559,036 to Wunsch discloses an apparatus for sequentially dispensing a plurality of solutions through an intravenous supply catheter to a patient. The system includes a disposable tubing manifold that is connected to each of the solutions to be administered. Valves mounted upon a manifold plate stop flow of solution through the branches of the tubing manifold which engages each branch. The quantity of solution dispensed is metered by a volumetric infusion pump and controlled by sequentially opening and closing the valves individually. Electronically operable motors or solenoids are connected to each valve for automatically opening and successively closing each valve. A sequencer-timer in accordance with a predetermined program controls the automatic energization and successive de-energization of each motor, one at a time, and successively energizes additional motors for intermittent individual operation through a pre-selected cycle of operation.
Furthermore, U.S. Pat. No. 4,710,166 to Thompson et al. discloses a system for sequentially administering to a patient fluids from a secondary fluid container and a primary fluid container at respective selected flow rates governed by an electromechanical device that includes a pump. The system includes a Y-connector upstream from the electromechanical device, a primary fluid line extending from the primary fluid container through a primary valve to the Y-connector, and a secondary fluid line extending from the secondary fluid container to the Y-connector through a secondary valve. An output flow line extends from the Y-connector to the pump associated with the electromechanical device.
Other relevant fluid delivery systems are disclosed in U.S. Pat. No. 6,889,074 and U.S. Patent Application Publication No. 2004-0162488 to Uber, III et al. (“Uber”) and U.S. Pat. No. 6,731,971 to Evans, III et al. (“Evans”). Generally, these patents disclose medical devices for delivery of contrast to a patient while allowing the adjustment of contrast concentration and injection parameters either before or during an injection procedure to provide patient specific dosing of contrast. Uber discloses a fluid delivery system comprising first and second sources of fluid medium, first and second pressurizing devices associated with the first and second sources of fluid medium, a fluid path operable to deliver the first and second fluid media to a balloon catheter inserted in a patient, and a control unit in communication with the pressurizing devices. Evans discloses a fluid delivery system similar to that disclosed by Uber but the first and second pressurizing devices are selectively operable to deliver the first fluid medium or the second fluid medium to the fluid path. This system is further directed to enabling the injection of fluid media into a plurality of patients. Generally, the system disclosed by Evans includes a fluid supply source providing multiple doses of fluid media, a metering device for measuring the doses, a pressurizing device to effect injection, a contamination prevention device disposed between the fluid source and patient and, if desired, and electronic control device.